Codeforces Round 501 (Div. 3)

7 problems from Codeforces Round 501 (Div. 3) (contest 1015), difficulty 800-2300. 5/7 solutions verified against sample I/O.

7 items

Codeforces Round 501 (Div. 3)

Div. 3 | 7 problems | 5/7 verified | Difficulty 800-2300 | 18m

# Problem Rating Tags Accepted Time ✓
A Points in Segments 800 implementation 22,434 1m 28s ✓
B Obtaining the String 1200 implementation 12,411 1m 35s ✓
C Songs Compression 1100 sortings 21,394 3m 28s ✓
D Walking Between Houses 1600 constructive-algorithms, greedy 8,960 4m 18s ✓
E1 Stars Drawing (Easy Edition) 1700 brute-force, dp, greedy 6,809 2m 3s
E2 Stars Drawing (Hard Edition) 1900 binary-search, dp, greedy 4,038 2m 52s
F Bracket Substring 2300 dp, strings 1,476 2m 16s ✓
Practice › Codeforces Solutions › Codeforces Round 501 (Div. 3) ›

CF 1015E2 - Stars Drawing (Hard Edition)

The grid contains two kinds of cells, filled and empty. We are allowed to place geometric objects called stars, where each star consists of one central filled cell and four straight arms extending in the four cardinal directions.
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CF 1015F - Bracket Substring

We are asked to build full valid bracket sequences of length 2n, and we want to count how many of those sequences contain a given string s as a contiguous block somewhere inside them. So conceptually, imagine all balanced parentheses strings of fixed size 2n.
codeforces competitive-programming dp strings Jun 16, 2026
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CF 1015D - Walking Between Houses

We are standing at the leftmost house in a long line of houses numbered from 1 to $n$. We must perform exactly $k$ moves, and each move consists of jumping from our current house to any different house.
codeforces competitive-programming constructive-algorithms greedy Jun 16, 2026
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CF 1015E1 - Stars Drawing (Easy Edition)

We are given a rectangular grid filled with two types of cells, occupied cells marked as and empty cells marked as .. The task is to explain the grid as a superposition of geometric objects called stars.
codeforces competitive-programming brute-force dp greedy Jun 16, 2026
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CF 1015C - Songs Compression

We are given a collection of songs, each with an original size and a smaller size if we choose to compress it. All songs must be copied onto a flash drive whose total capacity is fixed. The only decision available is which songs to compress.
codeforces competitive-programming sortings Jun 16, 2026
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CF 1015B - Obtaining the String

We are given two strings of equal length, where one string represents a starting arrangement of characters and the other represents a target arrangement. The only allowed operation is swapping two adjacent characters in the starting string.
codeforces competitive-programming implementation Jun 16, 2026
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CF 1015A - Points in Segments

We are given a one-dimensional number line from 1 to m, and several closed intervals placed on it. Each interval covers every integer point between its endpoints, including both ends.
codeforces competitive-programming implementation Jun 16, 2026